This blog delves into the often-hidden world of solar cables, exploring the different types used, the key factors determining their quality, how unscrupulous vendors cut corners, how you can avoid being fooled and ensure your solar plant thrives for years to come and and most importantly how budget-grade cables can sabotage your solar investment.
- The dream of a clean, independent energy source often leads homeowners and businesses to embrace solar power.
- However, the allure of budget-friendly solar installations can sometimes turn into a nightmare of underperformance, energy losses, overheating, frequent repairs, and even fire & safety hazards.
- While many factors contribute to the success of a solar plant, one often-overlooked element plays a surprisingly critical role: cable quality.
The Impact of the cables in Solar plant:
🏞️ Think of your solar plant as the blood circulatory system of the human body:
- 🔆The solar panels are the organs generating energy.
- ❤️The inverter is the heart converting it.
- 🔌The cables function as the veins and arteries transporting this vital energy.
Just as clogged or weak blood vessels can cripple the human body, substandard cables can significantly hinder the efficiency and longevity of your solar investment.
Key Factors to Assess Cable Quality
Conductor Material:
The conducting material in a cable carries electric current from one point to another with minimal resistance. Its conductivity, strength, and durability directly affect the cable’s efficiency, safety, and performance in any electrical system. The different types of conducting materials are:
Copper (Cu):
- High Conductivity – Superior performance, minimal energy loss.
- Durability – Better resistance to corrosion and wear.
- Flexibility – Easier installation in complex layouts.
- Cost Consideration – More expensive, but worth it long-term.
Durability – Better resistance to corrosion and wear.
Cost Consideration – More expensive, but worth it long-term. 
Copper Variants:
Annealed Copper: Softer, used in flexible wires.
Tinned Copper: Coated with tin for corrosion resistance (used in marine, solar).
Bare Copper: Used where no corrosion issues.
Aluminum:
- Cost-Effective – Budget-friendly option.
- Lightweight – Easier for long-distance installations.
- Trade-off – Lower conductivity, prone to oxidation.
Cost-Effective – Budget-friendly option.
Lightweight – Easier for long-distance installations.🔸 Copper-Clad Aluminum (CCA)
Aluminum core with a thin copper coating.
Lower cost than copper, better conductivity than pure aluminum.
Used in low-power or budget-friendly applications.
Not ideal for high-load or critical power systems.
Conductor Purity and Type
1. Pure Copper– ≥99.97% is recommended for optimal conductivity, complaint to IS 8130 / IEC 60228 Class 5 or Class 6
2. Recycled Copper:
Made from scrap copper, melted and reprocessed.
Purity varies (can range from 95%–99%).
Often lacks proper refining and may contain impurities like tin, iron, or aluminum.
Drawbacks:
Lower electrical conductivity.
Higher resistance → more energy loss.
Shorter life span, prone to corrosion.
Not compliant with IS/IEC standards for critical uses.
🧪 2. Mixed Copper (Alloyed or Impure)
May include aluminum-copper mix, or copper-coated aluminum (CCA).
Significantly cheaper but not suitable for high-load or long-term applications.
⚠️ Risks:
Looks like copper, but performs poorly.
High voltage drop, overheating risk.
Fails ISI/IEC tests.
Cable Sheath play important role:
The Copper or Aluminum conductor is covered by a casing (sheath) in the cable. It has dual purpose to provide insulation and sheathing. The expected requirement from casing material to function both as an insulation and seathing material are given below seperately:
Insulation: It is the non-conductive layer (with high dielectric strength) surrounding the conductor, preventing current leakage and short circuits.
Roles of outer layer as an insulating material:
- Electrical Safety: Prevents electrical shocks by providing a non-conductive barrier.
- Thermal Protection: Helps regulate temperature, preventing overheating.
- Durability: Resists physical damage, ensuring longer cable life in tough environments.
- Weather Resistance: Protects cables from rain, UV exposure, and extreme temperatures.
- Flame Retardant: Reduces fire risks by preventing the spread of flames.
Sheathing: Sheathing is the outer protective layer of a cable that safeguards the internal conductors and insulation from physical damage, environmental factors, and electrical hazards.
- Mechanical Protection: Shields cables from abrasion, cuts, and impacts.
- Environmental Protection: Safeguards cables against chemicals, moisture, and UV rays.
- Flexibility: Allows cables to bend and move without compromising protection.
- Corrosion Resistance: Protects cables from rust and corrosion, especially in outdoor or industrial settings.
- Aesthetic Appeal: Often designed to be smooth and clean, improving the visual presentation of cables.
The insulation and sheathing material can be same or different.
Material Options:
- XLPE – High thermal/mechanical resistance.
- Polyvinyl PVC – Budget-friendly but less thermally stable
XLPE – High thermal/mechanical resistance.
Polyvinyl PVC – Budget-friendly but less thermally stableChallenges in Solar Plants Affecting Cable Performance
UV Radiation (Sunlight Exposure)
Challenge: Prolonged UV exposure degrades conventional insulation like PVC or PE.
Impact: Cracks in insulation, exposure of conductors, and long-term failure.
Solution:
Use UV-resistant XLPE or Rubber insulation.
Sheath that has been used should have FRLS (Fire Resistance Low Smoke) or higher compliance like LSZH (Low Smoke Zero Halogen) .
Compliance: EN 50618 or TÜV 2PfG 1169 standards.
High Voltage Stress (600V to 1500V DC)
Challenge: Solar cables operate at high voltages continuously, stressing the dielectric layer.
Impact: Partial discharge, insulation breakdown, fire risk.
Sheath/Insulation Solution:
Use XLPE insulation for high dielectric strength.
Dual-layer insulation (core + sheath) with high-voltage tested FRLS/LSZH sheathing.
Cables like H1Z2Z2-K rated for 1500V DC are ideal.
Ambient Heat (Up to 70–75°C on Rooftops)
Challenge: Ambient heat combined with current load raises conductor temperature.
Impact: Accelerated aging, insulation softening, derating of cable capacity.
Sheath/Insulation Solution:
Use insulation rated for 90°C continuous, 120°C short-term (e.g., XLPE).
Choose sheathing material like Rubber or FRLS/LSZH that withstands heat cycles without cracking.
Water and Moisture Ingress (Rain, Dew, Humidity)
Challenge: Water penetrates poorly sealed cables or connectors.
Impact: Corrosion, short circuits, insulation failure.
Sheath/Insulation Solution:
Use moisture-resistant cross-linked compounds (XLPE) for both insulation and sheath.
Opt for solid-extruded LSZH sheath to prevent water entry.
Ensure double-compression glands and sealed conduit entries.
Chemical Exposure (Bird Droppings, Pollution)
Challenge: Rooftop and industrial sites expose cables to acidic or corrosive substances.
Impact: Sheath degradation, cracks, insulation hardening.
Sheath/Insulation Solution:
Use chemical-resistant FRLS/LSZH sheath.
Prefer TPE or Rubber where chemical splash or fumes are expected.
Mechanical Damage (Wind, Rodents, Human Activity)
Challenge: Cable movement, rodent attacks, or accidental impacts.
Impact: Abrasions, insulation nicks, open circuits.
Sheath/Insulation Solution:
Use abrasion-resistant outer sheaths like Rubber or TPU.
Install cables in GI conduits or UV-stabilized PVC pipes for added mechanical protection.
Recommended cable for the Solar Plant :
Before discussing on this, it is important to know what is armored cable and what is fire resistant cable.
What is an Armoured Cable?
Armoured Cable is a power cable with a protective metal layer (armour) between the insulation and the outer sheath. This metallic armour (usually steel or aluminum wires or tape) provides mechanical protection.
📌 Uses: It is used where mechanical strength is required, like laying of cables in trenches, Industrial environments, or areas prone to mechanical damage or rodents.
🔥 2. What is a Fire-Resistant Cable?
Fire-resistant cables maintain circuit integrity during a fire, meaning they keep working for a defined period even when exposed to flame and high temperatures.
🔥 Types:
- FR (Flame Retardant): Delays the spread of flame.
- FRLS (Flame Retardant Low Smoke): Reduces smoke and toxic gas emission.
- LSZH (Low Smoke Zero Halogen): Ideal for confined/public spaces – emits no halogens and very low smoke.
Based on the above said features and information, here is the summary of recommended cables which should be used at different power points of the solar plant
Recommended Cable at key solar Plant points
✅ Final Recommendations
Insulation: Always go for XLPE or EB-XLPE for both DC and AC segments. Avoid PVC insulation for solar.
Sheath: Use LSZH or TPU in open/exposed runs; FRLS for indoor or battery zones.
Armour: Mandatory for underground or industrial routes; optional in rooftop/raised structures.
Voltage: Ensure 1.5 kV rated DC cables from panel to inverter; 1.1 kV AC from inverter to LT panels.
6️⃣ Impact of Ignoring Cable Quality on the Solar Plant
| Property | Compromise | Impact |
|---|---|---|
| 1. 🔌 Cheap or Substandard Conductor (Copper/Aluminum) | Use of Aluminum or CCA (Copper-Clad Aluminum) instead of pure copper | ⚡ Higher resistance → voltage drop and energy loss |
| Lower strand count or under-sized core | 🔥 Overheating, risk of fire, cable burnout under load | |
| Impure copper with high resistivity | 💸 Poor efficiency → increased power loss → revenue loss over time | |
| 2. 🔥 Inferior Insulation Material (PVC instead of XLPE/EB-XLPE) | Use of PVC instead of XLPE | ❌ Low thermal resistance → cracks under sunlight, failure in 2–3 years |
| Non-TÜV/EN50618-rated XLPE | ⚠️ No guarantee of electrical strength → leakage current or insulation breakdown | |
| Use of recycled plastic | ⚠️ Contaminants may degrade insulation rapidly → shock or short circuit risk | |
| 3. 🌞 Cheap or Recycled Sheathing Material (PVC instead of LSZH/TPU) | Use of PVC in UV-exposed runs | 🌤️ UV degradation → cracks, water ingress, insulation exposure |
| Recycled or thin sheath | 🐀 No rodent resistance → chewing damage, short circuit | |
| No flame retardance | 🔥 Fire spread in case of fault → higher damage | |
| Not LSZH | 💀 Releases toxic halogens during fire → unsafe for people/environment | |
| 4. 🏷️ Fake or Incorrect Certifications | Fake IS, EN, or TÜV markings | ❌ Misleading safety claims → you lose warranty, insurance or compliance |
| No test reports or batch traceability | ⚠️ Unknown origin → no accountability for failure | |
| Non-compliance with IS 7098 / EN50618 | 🚫 Fails regulatory checks during audits or tenders |
The Long Term Impact of compromise in the cable quality
7️⃣Knowing the Different Ways Vendors Curtail Costs
⚠️How the cheap vendors compromise on the quality of cable?
⚠️ How Cheap Vendors compromises on sheathing and insulation materials
⚠️ Few Other ways the customer gets cheated: What Budget Vendors Won’t Tell You
Many vendors in the market cut costs by compromising on cable quality. Since many users are not aware they put any of the above low quality cables.
Apart from this there can be few other reasons how they curtail costs :
🔻 1. Inferior Conductor Quality
Use of recycled or impure copper
Increases electrical resistance and heat generation
Reduces energy efficiency and lifespan
🔻 2. Fake Insulation Claims
Label as XLPE but use PVC
Cracks and degrades in a few years under sun/heat
🔻 3. Misleading Certifications
Fake TÜV or EN labels on non-compliant cables
No testing or international standard compliance
🔥 Consequences:
Lower solar output (2–5% drop)
Risk of cable failure, fire, inverter damage
Higher maintenance and replacement cost
8️⃣ How You Can Verify the Cable Quality:
✅ How to Verify and Avoid Being Cheated
🧾 Conclusion
While the initial cost of a premium DC cable may be higher, it pays off in terms of efficiency, safety, and lifespan. If you’re investing in a solar plant expected to run for 25+ years, don’t let poor cabling be the weakest link.
🚫 Say no to budget traps.
✅ Say yes to long-term performance.
